Method of making briquetting rolls



June 4, 1940. KQMAREK 2,203,200

- METHOD OF MAKING BRIQUETTZNG ROLLS Filed July 15, 337 2 Sheets-Sheet 115 arwe/wto' Gwfau leovnafa as Z Z v M4404 1M y.

June 4, 1940.

s. KOMAREK J 2,203,200

I nun-non OF MAKING amqumrxue ROLLS Filed July 15, 193'; 2 Sheets-Sheet2 4 Patented June 4, 1940 UNITED STATES METHOD OF MAKING BRIQUETTINGROLLS Gustav Komarek, Chicago, 111.,

assignor to Komarek-Greavess and Company, Chicago, 111., a corporationof Illinois Application July 15, 1937, Serial No. 153,851

5 Claims.

The present invention relates to the art of briquetting and is moreparticularly directed to the rolls for molding briquettable materialinto desired shapes.

I-Ieretofore, and at the present time, these rolls have had moldingpockets of a character to produce two general shapes of briquettes, (a)the over-stuffed pillow type; and (b) a more rounded ype.

Because of the weakness presented by having four sharp corners in theover-stuffed pillow type of briquette, whereby objectionable fines areproduced during handling and storing, this briquette shape is notregarded as preferable. The industry has therefore turned to the moreabrasion resistant rounded type in which such sharp, weak corners areeliminated.

The manufacture of the rounded type of briquette has been attended withthe necessity, that the molding pockets of the rolls must be disposed instaggered relation in order to avoid excess dead or void spaces on thesurfaces of the roll between the pockets. However, with such expedient,overcompression or under-compression of the briquette material occurs,with the result that (1) the briquettes lack uniformity, (2) splittingor clam shelling frequently develops in the case of over-compression,and (3) the briquette structure is weak and is not firm and solid wherethere has been an insufiicient amount of compression.

The present invention aims to efficiently produce briquettes of therounded type and to overcome the aforesaid difficulties by providingrolls having the molding pockets arranged in transverse rowscircumferentially of the rolls. l hat is to say, the pockets asdistinguished from being velop clam shelling and possess the desiredfirm character.

I am familiar with the fact that in the manufacture of the over-stuffedpillow type of briquette, it is customary to form the square edged upockets in transverse alignment on the rolls, and

that to accomplish this result it is necessary in order to form apocket, to resort to two or more cutting operations. The expense ofthis, and the difficulty of producing precisely accurate pockets which,of course, must register in the respective rolls for molding purposes,will be appreciated. Moreover, as will be later explained, the making ofpockets for rounded type briquettes is a distinct problem.

The present invention further comprehends a method of forming pockets ofthe required rounded contour in the rolls by one cutting operation. Thatis to say, I use a single cutting tool having the precise configurationand dimension ratio which it is desired that the pocket finally possessand impart to the briquette.

The cutting ope-ration is conducted preferably by a rotating cuttingmember working simultaneously upon a pair of opposed rolls. Pairs ofmating pockets may thus be cut successively by moving the cuttertransversely across the rolls, or two or more pairs may be cutsimultaneously. In this manner, pockets of uniform shape and dimensionare produced in the respective rolls and in the proper relation toregister for molding purposes. The rolls with the pockets therein may beformed by casting, if desired.

The advantages of rolls having transversely aligned pockets and formedby a single cutting operation will be apparent. However, these resultsare only attained by a critical control of the curvature of the bottomand sides of the individualpockets. That is to say, my rounded type ofbriquette has a curved top and bottom meeting respectively at two endsof thebriquette along substantially straight median lines and the twosides of the briquette are substantially elliptical in construction andare convexly curved both longitudinally and transversely. I havediscovered that if the ratio of the radii of curvature between the radiiat the convex sides of the briquette (the longitudinal and transverseradii of curvature at each of the convex sides being substantially thesame), and the radii of curvature of the top and bottom of thebriquette, (the radii curvature of the top and bottom of the briquettebeing substantially the same) is maintained at substantially two to one,that it is I the solution of the problem of eliminating (a) theheretofore regarded necessary expedient of staggering the pockets formaking rounded briquettes, and (b) the objectionable over-stuffedpillow-shaped type of briquette. It also (0) enables for the first time,the forming efficiently of the preferred rounded briquettes of uniformquality without the diificulties heretofore encountered.

In order that the invention may be fully understood, I have illustratedin the accompanying drawings a preferred type of briquette, briquetteroll and method of manufacture, which may be modified in various wayswithout departing from the spirit of the invention.

Referring to the drawings,

Figure 1 is a diagrammatic side elevation of a pair of briquette rollsformed with pockets in accordance with this invention;

Figure 2 is a combination view showing at the left the surface of a rollin elevation, and at the right in transverse section (on the line 2-2 ofFigure l) the registering engagement of the pockets at the point oftangency of the rolls, for compressing and molding the briquettematerial;

Figure 3 is an enlarged perspective view of the surface of a roll;

Figure 4 is a top elevation of a rounded briquette made in accordancewith this invention;

Figure 5 is an end elevation of the briquette of Figure 4;

Figure 6 is a perspective view of the briquette of Figure 4;

Figure 7 is a transverse sectional view showing the manner in whichpockets are formed in a pair of rolls; and

Figure 8 is a vertical sectional view illustrating how the pockets areformed in a pair of rolls and taken on the line 88 of Figure '7.

Referring to Figure 1, I have illustrated at l 0 a pair of similarbriquette molding rolls which are suitably supported for rotation atpredetermined speeds in the usual manner to perform the briquettingoperation. These rolls are provided in their peripheries with rows ofregistering pockets H. The pockets extend in both transverse andcircumferential lines as shown in Figure 2, and the pockets of one rollare in registering relation precisely with the pockets of the other rollas shown at 2 in Figure 1.

Any usual briquettable material, e. g., a combustible mixture, iscontinuously fed downwardly as indicated by the arrow into the upperbight of the rolls and is thus supplied by gravity to the pockets andmolded to briquette form as the rolls rotate.

As shown in Figures 3 and 8, the bottoms iii of the pockets arecontinuously curved inwardly and downwardly from one straight end edgeIt at the roll surface to the other. The sides l5 are semielliptical incontour and are convexly curved both longitudinally and transverselyoutwardly and upwardly from the bottom. At their inner or bottom edges,the sides merge with the bottom throughout its length on a curve asshown at l6, while their outer edges are outwardly curved at the rollsurface as shown at ll. In this manner, and referring to Figures 4, 5and 6, it will be apparent that the briquette will have a desirablerounded form, and will be devoid of sharp edges orweak square corners.

As heretofore stated, the radius of curvature of the bottoms 13 of thepockets (which form the top and bottom molding surfaces) has a directrelation to the radii of curvature of the convexly curved sides l5 toform strong, firm and uniform, abrasion resistant briquettes devoid ofany sharp, weak portions. That is to say, I have discovered that thiscritical relationship is observed, permits pockets for molding therounded type briquettes to be arranged side by side in transverse rows(and circumferentially in line) whereby (l) at any time, the sameportions of the briquette material in any transverse row of pockets aresubjected to equal pressure, (2) the pockets may be cut to the requiredshape and dimension by a single cutting operation, and (3) objectionabledead or void surface is avoided. I have found the ratio between theradius and curvature of the radii of the transversely and.longitudinally curved sides 15 and the radius of curvature of the bottoml3 to be critical and substantially two to one. That is to say, theradii of curvature of the convexly curved sides l5 should be at leasttwice that of the radius of curvature of the bottom l3. Rolls having thepockets constructed and arranged in the manner described for making therounded type of briquettes will eliminate the present unsatisfactoryrolls in which the pockets are disposed in staggered relation.

The present invention embodying pockets for making rounded briquettestransversely aligned in rows is to be distinguished from the practice ofhaving the pockets for making over-stuffed pillow type of briquettessimilarly arranged. In the latter type, the walls of the pockets are allof the same contour to produce a briquette. having upper and lowerpyramids joined at their bases, each pyramid. consisting of four equaltriangular sides. jointure is square. In the case of the roundedbriquette, however, the two similar semi-elliptic sides l5 of the pocketI I are different in contour from the curved bottom of the pocket andthe molding operations in actual practice have evidenced a distinctproblem. That is to say, in molding the rounded type of briquette withthe pockets staggered as has heretofore been the practice, clam shellinghas frequently occurred due to over-compression, the briquettes have notbeen uniform in structure, and further, often disclose weakened portionsdue to under-compression. This is apparently due to the fact that in thecase of the ockets for the rounded briquettes, the pressure increases asthe point of tangency of the rolls moves toward the deepest and widestpart of the respective opposed pockets and in a similar mannerprogressively decreases as the point of tangency moves away from thewider and deeper portions of the opposed pockets. Thus, with thebriquettes in staggered relation, alternate adjacent briquettes alongany line of tangency are being subjected to alternating high or lowpressures at different points on the pocket areas dependent upon wherethe line of tangency passes across the respective pockets. Consequently,over-compression with resulting clam shelling occurs with some of thebriquettes due to the fact that excess material cannot be expelledupwardly, and hence, becomes locked in the pockets, while in the case ofother briquettes underc npression takes place, forming weak briquettes.

On the other hand, with the pockets for making rounded briquettesdisposed in alignment, it is possible to make an abrasion resistantproduct without recourse to staggering the pockets in order to avoiddead or void space on the roll surface. Furthermore, and of particularimportance, it is possible to make briquettes Thus, the median line orline of which are entirely uniform in structure due to the fact, asexplained above, that equal pressure is exerted on the same alignedportions of each briquette in a row at the same time in the rotativemovement of the rolls. Apparently,

uniform feeding takes places to each of the pockets and the pressure isable to equally relieve each pocket of excess material. Rounded type ofbriquettes produced in accordance with this invention are free of clamshelling and are uniformly solid and firm in structure.

Referring to Figures 4, 5 and 6, I have shown a rounded type ofbriquette produced in accordance with the present invention. It will benoted that the curved bottom Eta and top it?) meet along straight medianlines ii) at opposite ends of the briquette, and due to the radius ofcurvature, the contour along this median line is curved. Further, itwill be observed that the substantially elliptical sides 20 are convexlycurved. Likewise, the areas along the median line I9 are bothlongitudinally and transversely curved. Also, the corners of thebriquettes are rounded due to the configuration of the pockets, asshown, for example, at 2i. There is thus formed an abrasion resistantarticle free of any pointed or sharp portions which would degrade underthe normal conditions of handling and storage to which briquettes aresubjected.

As heretofore stated, the pockets of the present invention are formed bya single cutting operation which may be of any suitable type such asmachining or milling. Referring to Figures 8 and 9, I have, by way ofexample, illustrated a shaft 25 carying a milling cutter 26 at one end.The milling cutter 26 has substantially the precise ratio of dimensionsand contour to be imparted to the pockets [3 as shown in Figures 2 and 3and the briquette as shown in Figures 4, 5 and 6.

The milling cutter is preferably rotated withv the shaft 25 to formpockets in both rolls simultaneously, as shown in Figures '7' and 8,with the rolls having their axes parallel in the position which theywill occupy during the briquetting operation. Of course, the cuttingoperation may be conducted upon single rolls if desired, but this is notpreferred.

As many cutters may be disposed on the shaft 25 as desired or as can beaccommodated, but it is preferred to use a single milling head 26 andcut pairs of pockets successively in transverse rows as shown in Figure7 across the roll, indexing the rolls each time a new transverse line ofpockets is to be formed and continuing the procedure described until theformation of pockets over the entire periphery of the rolls is completedas shown in Figures 2 and 3. As a result, the pockets are uniform incontour and dimension and have a precise mating relation with each otherfor molding purposes. In this cutting operation, the pockets aredisposed in closely spaced relation and the area represented by the voidor dead spaces is insufficient to affect the briquetting operation.

The rolls ID are of the usual metallic construction, and the cuttingmember 26 is likewise of suitable metallic composition and hardness toperform the milling operation.

Referring further to Figures '7 and 8, it will be noted that the shaft25 rotates on an axis parallel to the axes of the rolls while the rollsare being moved toward the cutter to form pockets of the above describedconfiguration, and that the milling head is directed so as to form thesides [5 parallel with the end walls of the rolls. only are the pocketsin transverse alignment, but they are in annular or peripheral alignmentas well.

I have discovered that in the manufacture of products of the generalshape, i. e., as described above, it is not necessary to control orregulate plasticity of the mix within the narrow limits which areabsolute requisites when the pockets are staggered. In other words,rolls having the pockets aligned transversely are affected to a muchless degree by lack of plasticity. This is to be distinguished from verycareful control of the mix which is necessary in connection withstaggered roll pockets which appear satisfactory only when the mix has avery carefully regulated plastic condition. I believe the effectprobably to be due to the plastic condition and its relation to theirregular pressure exerted on adjacent pockets When the pockets arestaggered. With staggered pockets, the material under compression at theline of tangency is in more than one transverse row because the adjacentbriquettes merge into this line of tangency. When plasticity is high,the excess amount can be disgorged, but, as plasticity decreases, itbecomes more difficult to disgorge the excess material with staggeredpockets since the several rows of briquettes are merged into the line oftangency. With the pockets in one transverse line, as herein described,every pocket has the same area under compression simultaneously and thedisgorging of excess material being not so difiicult, will take placewith a very low degree of curved top and bottom, and convexly curvedsides.

I claim:

The method of making briquetting rolls comprising acting upon a metalroll transversely of its periphery with a cutting tool having theprecise dimensions and contour of a briquette molding pocket to beformed in said roll, forming a plurality of similar shaped and sizedpockets in alignment transversely across the roll, and. continuing theprocedure until the entire periphery of the roll has been formed withrows of transversely aligned pockets, said cutting operationconstituting the only cutting step in the formation of each pocket andeach pocket having as a result of such single cutting operation thefinal configuration which it is desired to impart to the pocket and to abriquette.

2. The method of making briquetting rolls comprising acting upon a metalroll transversely of its periphery with a cutting tool having theprecise dimensions and contour of a briquette molding pocket to beformed in said roll, forming a plurality of similar shaped and sizedpockets in alignment transversely across the roll, said pockets havingbottoms continuously curved from end to end and convexly curved sides,and continuing the procedure until the entire periphery of the roll hasbeen formed with rows of transversely aligned pockets, said cuttingoperation constituting the only cutting step in the formation of eachpocket and each pocket having as a result of such single cuttingoperation the final configuration which it is desired to impart to thepocket and to a briquette.

3. The method of making briquetting rolls com- As a result of thecutting operation, not

prising acting upon a metal roll transversely of its periphery with acutting tool having the precise dimensions and contour of a briquettemolding pocket to be formed in said roll, forming a plurality of similarshaped and sized pockets in alignment transversely across the roll, eachpocket having a bottom continuously curved from one end edge at thesurface of the roll to the other and transversely and longitudinallycurved sides extending outwardly and upwardly from the bottoms, theratio of the radii of curvature of said sides to the radius of curvatureof the bottom being substantially two to one, and continuing theprocedure until the entire periphery of the roll has been formed withrows of transversely aligned pockets, said cutting operationconstituting the only cutting step in the formation of each pocket andeach pocket having as a result of such single cutting operation thefinal configuration which it is desired to impart to the pocket and to abriquette.

4. The method of making briquetting rolls comprising actingsimultaneously upon a pair of 0pposed metal rolls transversely of theirperipheries with a cutting tool having the precise dimensions andcontour of mating briquette molding pockets to be formed in said rolls,forming a plurality of similar shaped and sized pockets in alignmenttransversely across the rolls, and continuing the procedure until theentire periphery of each roll has been formed with rows of transverselyaligned registering pockets, said cutting operation constituting theonly cutting step in the formation of each pocket and each pocket havingas a result of such single cutting operation the final configurationwhich it is desired to impart to the pocket and to a briquette.

5. The method of making briquetting rolls comprising acting upon a metalroll with a cutting tool having substantially the precise dimensions andcontoLu' of a briquet molding pocket to be formed in said roll andcutting a pocket having a bottom continuously curved from end to end andsides convexly curved both longitudinally and transversely upwardly andoutwardly from the bottom, and forming a plurality of such pockets ofsimilar shape and size in transverse and peripheral alignment.

GUSTAV KOMAREK;

